diff options
Diffstat (limited to 'arch/s390/kernel/kprobes.c')
| -rw-r--r-- | arch/s390/kernel/kprobes.c | 178 |
1 files changed, 119 insertions, 59 deletions
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index 014d4729b134..1e4c710dfb92 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -29,6 +29,7 @@ #include <linux/module.h> #include <linux/slab.h> #include <linux/hardirq.h> +#include <linux/ftrace.h> #include <asm/cacheflush.h> #include <asm/sections.h> #include <asm/dis.h> @@ -58,12 +59,23 @@ struct kprobe_insn_cache kprobe_dmainsn_slots = { .insn_size = MAX_INSN_SIZE, }; -static void __kprobes copy_instruction(struct kprobe *p) +static void copy_instruction(struct kprobe *p) { + unsigned long ip = (unsigned long) p->addr; s64 disp, new_disp; u64 addr, new_addr; - memcpy(p->ainsn.insn, p->addr, insn_length(p->opcode >> 8)); + if (ftrace_location(ip) == ip) { + /* + * If kprobes patches the instruction that is morphed by + * ftrace make sure that kprobes always sees the branch + * "jg .+24" that skips the mcount block + */ + ftrace_generate_nop_insn((struct ftrace_insn *)p->ainsn.insn); + p->ainsn.is_ftrace_insn = 1; + } else + memcpy(p->ainsn.insn, p->addr, insn_length(*p->addr >> 8)); + p->opcode = p->ainsn.insn[0]; if (!probe_is_insn_relative_long(p->ainsn.insn)) return; /* @@ -79,25 +91,14 @@ static void __kprobes copy_instruction(struct kprobe *p) new_disp = ((addr + (disp * 2)) - new_addr) / 2; *(s32 *)&p->ainsn.insn[1] = new_disp; } +NOKPROBE_SYMBOL(copy_instruction); static inline int is_kernel_addr(void *addr) { return addr < (void *)_end; } -static inline int is_module_addr(void *addr) -{ -#ifdef CONFIG_64BIT - BUILD_BUG_ON(MODULES_LEN > (1UL << 31)); - if (addr < (void *)MODULES_VADDR) - return 0; - if (addr > (void *)MODULES_END) - return 0; -#endif - return 1; -} - -static int __kprobes s390_get_insn_slot(struct kprobe *p) +static int s390_get_insn_slot(struct kprobe *p) { /* * Get an insn slot that is within the same 2GB area like the original @@ -111,8 +112,9 @@ static int __kprobes s390_get_insn_slot(struct kprobe *p) p->ainsn.insn = get_insn_slot(); return p->ainsn.insn ? 0 : -ENOMEM; } +NOKPROBE_SYMBOL(s390_get_insn_slot); -static void __kprobes s390_free_insn_slot(struct kprobe *p) +static void s390_free_insn_slot(struct kprobe *p) { if (!p->ainsn.insn) return; @@ -122,8 +124,9 @@ static void __kprobes s390_free_insn_slot(struct kprobe *p) free_insn_slot(p->ainsn.insn, 0); p->ainsn.insn = NULL; } +NOKPROBE_SYMBOL(s390_free_insn_slot); -int __kprobes arch_prepare_kprobe(struct kprobe *p) +int arch_prepare_kprobe(struct kprobe *p) { if ((unsigned long) p->addr & 0x01) return -EINVAL; @@ -132,54 +135,79 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) return -EINVAL; if (s390_get_insn_slot(p)) return -ENOMEM; - p->opcode = *p->addr; copy_instruction(p); return 0; } +NOKPROBE_SYMBOL(arch_prepare_kprobe); -struct ins_replace_args { - kprobe_opcode_t *ptr; - kprobe_opcode_t opcode; +int arch_check_ftrace_location(struct kprobe *p) +{ + return 0; +} + +struct swap_insn_args { + struct kprobe *p; + unsigned int arm_kprobe : 1; }; -static int __kprobes swap_instruction(void *aref) +static int swap_instruction(void *data) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); unsigned long status = kcb->kprobe_status; - struct ins_replace_args *args = aref; - + struct swap_insn_args *args = data; + struct ftrace_insn new_insn, *insn; + struct kprobe *p = args->p; + size_t len; + + new_insn.opc = args->arm_kprobe ? BREAKPOINT_INSTRUCTION : p->opcode; + len = sizeof(new_insn.opc); + if (!p->ainsn.is_ftrace_insn) + goto skip_ftrace; + len = sizeof(new_insn); + insn = (struct ftrace_insn *) p->addr; + if (args->arm_kprobe) { + if (is_ftrace_nop(insn)) + new_insn.disp = KPROBE_ON_FTRACE_NOP; + else + new_insn.disp = KPROBE_ON_FTRACE_CALL; + } else { + ftrace_generate_call_insn(&new_insn, (unsigned long)p->addr); + if (insn->disp == KPROBE_ON_FTRACE_NOP) + ftrace_generate_nop_insn(&new_insn); + } +skip_ftrace: kcb->kprobe_status = KPROBE_SWAP_INST; - probe_kernel_write(args->ptr, &args->opcode, sizeof(args->opcode)); + probe_kernel_write(p->addr, &new_insn, len); kcb->kprobe_status = status; return 0; } +NOKPROBE_SYMBOL(swap_instruction); -void __kprobes arch_arm_kprobe(struct kprobe *p) +void arch_arm_kprobe(struct kprobe *p) { - struct ins_replace_args args; + struct swap_insn_args args = {.p = p, .arm_kprobe = 1}; - args.ptr = p->addr; - args.opcode = BREAKPOINT_INSTRUCTION; stop_machine(swap_instruction, &args, NULL); } +NOKPROBE_SYMBOL(arch_arm_kprobe); -void __kprobes arch_disarm_kprobe(struct kprobe *p) +void arch_disarm_kprobe(struct kprobe *p) { - struct ins_replace_args args; + struct swap_insn_args args = {.p = p, .arm_kprobe = 0}; - args.ptr = p->addr; - args.opcode = p->opcode; stop_machine(swap_instruction, &args, NULL); } +NOKPROBE_SYMBOL(arch_disarm_kprobe); -void __kprobes arch_remove_kprobe(struct kprobe *p) +void arch_remove_kprobe(struct kprobe *p) { s390_free_insn_slot(p); } +NOKPROBE_SYMBOL(arch_remove_kprobe); -static void __kprobes enable_singlestep(struct kprobe_ctlblk *kcb, - struct pt_regs *regs, - unsigned long ip) +static void enable_singlestep(struct kprobe_ctlblk *kcb, + struct pt_regs *regs, + unsigned long ip) { struct per_regs per_kprobe; @@ -199,10 +227,11 @@ static void __kprobes enable_singlestep(struct kprobe_ctlblk *kcb, regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT); regs->psw.addr = ip | PSW_ADDR_AMODE; } +NOKPROBE_SYMBOL(enable_singlestep); -static void __kprobes disable_singlestep(struct kprobe_ctlblk *kcb, - struct pt_regs *regs, - unsigned long ip) +static void disable_singlestep(struct kprobe_ctlblk *kcb, + struct pt_regs *regs, + unsigned long ip) { /* Restore control regs and psw mask, set new psw address */ __ctl_load(kcb->kprobe_saved_ctl, 9, 11); @@ -210,41 +239,43 @@ static void __kprobes disable_singlestep(struct kprobe_ctlblk *kcb, regs->psw.mask |= kcb->kprobe_saved_imask; regs->psw.addr = ip | PSW_ADDR_AMODE; } +NOKPROBE_SYMBOL(disable_singlestep); /* * Activate a kprobe by storing its pointer to current_kprobe. The * previous kprobe is stored in kcb->prev_kprobe. A stack of up to * two kprobes can be active, see KPROBE_REENTER. */ -static void __kprobes push_kprobe(struct kprobe_ctlblk *kcb, struct kprobe *p) +static void push_kprobe(struct kprobe_ctlblk *kcb, struct kprobe *p) { kcb->prev_kprobe.kp = __this_cpu_read(current_kprobe); kcb->prev_kprobe.status = kcb->kprobe_status; __this_cpu_write(current_kprobe, p); } +NOKPROBE_SYMBOL(push_kprobe); /* * Deactivate a kprobe by backing up to the previous state. If the * current state is KPROBE_REENTER prev_kprobe.kp will be non-NULL, * for any other state prev_kprobe.kp will be NULL. */ -static void __kprobes pop_kprobe(struct kprobe_ctlblk *kcb) +static void pop_kprobe(struct kprobe_ctlblk *kcb) { __this_cpu_write(current_kprobe, kcb->prev_kprobe.kp); kcb->kprobe_status = kcb->prev_kprobe.status; } +NOKPROBE_SYMBOL(pop_kprobe); -void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, - struct pt_regs *regs) +void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) { ri->ret_addr = (kprobe_opcode_t *) regs->gprs[14]; /* Replace the return addr with trampoline addr */ regs->gprs[14] = (unsigned long) &kretprobe_trampoline; } +NOKPROBE_SYMBOL(arch_prepare_kretprobe); -static void __kprobes kprobe_reenter_check(struct kprobe_ctlblk *kcb, - struct kprobe *p) +static void kprobe_reenter_check(struct kprobe_ctlblk *kcb, struct kprobe *p) { switch (kcb->kprobe_status) { case KPROBE_HIT_SSDONE: @@ -264,8 +295,9 @@ static void __kprobes kprobe_reenter_check(struct kprobe_ctlblk *kcb, BUG(); } } +NOKPROBE_SYMBOL(kprobe_reenter_check); -static int __kprobes kprobe_handler(struct pt_regs *regs) +static int kprobe_handler(struct pt_regs *regs) { struct kprobe_ctlblk *kcb; struct kprobe *p; @@ -339,6 +371,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) preempt_enable_no_resched(); return 0; } +NOKPROBE_SYMBOL(kprobe_handler); /* * Function return probe trampoline: @@ -355,8 +388,7 @@ static void __used kretprobe_trampoline_holder(void) /* * Called when the probe at kretprobe trampoline is hit */ -static int __kprobes trampoline_probe_handler(struct kprobe *p, - struct pt_regs *regs) +static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { struct kretprobe_instance *ri; struct hlist_head *head, empty_rp; @@ -444,6 +476,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, */ return 1; } +NOKPROBE_SYMBOL(trampoline_probe_handler); /* * Called after single-stepping. p->addr is the address of the @@ -453,12 +486,30 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, * single-stepped a copy of the instruction. The address of this * copy is p->ainsn.insn. */ -static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) +static void resume_execution(struct kprobe *p, struct pt_regs *regs) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); unsigned long ip = regs->psw.addr & PSW_ADDR_INSN; int fixup = probe_get_fixup_type(p->ainsn.insn); + /* Check if the kprobes location is an enabled ftrace caller */ + if (p->ainsn.is_ftrace_insn) { + struct ftrace_insn *insn = (struct ftrace_insn *) p->addr; + struct ftrace_insn call_insn; + + ftrace_generate_call_insn(&call_insn, (unsigned long) p->addr); + /* + * A kprobe on an enabled ftrace call site actually single + * stepped an unconditional branch (ftrace nop equivalent). + * Now we need to fixup things and pretend that a brasl r0,... + * was executed instead. + */ + if (insn->disp == KPROBE_ON_FTRACE_CALL) { + ip += call_insn.disp * 2 - MCOUNT_INSN_SIZE; + regs->gprs[0] = (unsigned long)p->addr + sizeof(*insn); + } + } + if (fixup & FIXUP_PSW_NORMAL) ip += (unsigned long) p->addr - (unsigned long) p->ainsn.insn; @@ -476,8 +527,9 @@ static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) disable_singlestep(kcb, regs, ip); } +NOKPROBE_SYMBOL(resume_execution); -static int __kprobes post_kprobe_handler(struct pt_regs *regs) +static int post_kprobe_handler(struct pt_regs *regs) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); struct kprobe *p = kprobe_running(); @@ -504,8 +556,9 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs) return 1; } +NOKPROBE_SYMBOL(post_kprobe_handler); -static int __kprobes kprobe_trap_handler(struct pt_regs *regs, int trapnr) +static int kprobe_trap_handler(struct pt_regs *regs, int trapnr) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); struct kprobe *p = kprobe_running(); @@ -567,8 +620,9 @@ static int __kprobes kprobe_trap_handler(struct pt_regs *regs, int trapnr) } return 0; } +NOKPROBE_SYMBOL(kprobe_trap_handler); -int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) +int kprobe_fault_handler(struct pt_regs *regs, int trapnr) { int ret; @@ -579,12 +633,13 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) local_irq_restore(regs->psw.mask & ~PSW_MASK_PER); return ret; } +NOKPROBE_SYMBOL(kprobe_fault_handler); /* * Wrapper routine to for handling exceptions. */ -int __kprobes kprobe_exceptions_notify(struct notifier_block *self, - unsigned long val, void *data) +int kprobe_exceptions_notify(struct notifier_block *self, + unsigned long val, void *data) { struct die_args *args = (struct die_args *) data; struct pt_regs *regs = args->regs; @@ -616,8 +671,9 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, return ret; } +NOKPROBE_SYMBOL(kprobe_exceptions_notify); -int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) +int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) { struct jprobe *jp = container_of(p, struct jprobe, kp); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); @@ -635,13 +691,15 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) memcpy(kcb->jprobes_stack, (void *) stack, MIN_STACK_SIZE(stack)); return 1; } +NOKPROBE_SYMBOL(setjmp_pre_handler); -void __kprobes jprobe_return(void) +void jprobe_return(void) { asm volatile(".word 0x0002"); } +NOKPROBE_SYMBOL(jprobe_return); -int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) +int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); unsigned long stack; @@ -655,6 +713,7 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) preempt_enable_no_resched(); return 1; } +NOKPROBE_SYMBOL(longjmp_break_handler); static struct kprobe trampoline = { .addr = (kprobe_opcode_t *) &kretprobe_trampoline, @@ -666,7 +725,8 @@ int __init arch_init_kprobes(void) return register_kprobe(&trampoline); } -int __kprobes arch_trampoline_kprobe(struct kprobe *p) +int arch_trampoline_kprobe(struct kprobe *p) { return p->addr == (kprobe_opcode_t *) &kretprobe_trampoline; } +NOKPROBE_SYMBOL(arch_trampoline_kprobe); |